Techno-economic analysis of nitrogen-fixing cyanobacteria production for the food industry

Food production and the conventional agriculture and livestock sectors are facing important challenges, including the increasing global population and the need to handle all the industry processes more sustainably. Nitrogen-fixing cyanobacteria have the compelling ability to convert atmospheric dinitrogen into valuable compounds, which can be incorporated into the human and animal diet, such as proteins and pigments. This eliminates the dependence on nitrogen-based fertilizers in the process. The aim of the thesis is to carry out a techno-economic analysis of the processes regarding the achievement of different food products from the cultivation of nitrogen-fixing cyanobacterium Nostoc PCC 7120. The economic analysis is used to assess the profitability of an industrial-scale process that leads to the production of nutrient-rich biomass. This first product is also integrated into other process configurations for the achievement of potentially more profitable products: phycocyanin and probiotics. The operating variables are chosen to simulate a real plant in the South of Italy, operating for eleven months per year. To conduct economic analysis, a combination of literature data, experimental data, and real plant results is used. From the economic analysis conducted for the biomass production plant, the high-risk investment proved profitable, showing an Internal Rate of Return (IRR) of 30.66% and a Discounted PayBack Period (DPBP) of 4.5 years. Similarly, the branched process of biomass fermentation with Lactobacillus plantarum for probiotic production yielded highly favorable results, with an IRR of 152.8 % and a DPBP of two years. On the contrary, due to the high costs associated with implementing extraction lines, the profitability analysis for phycocyanin extraction indicated an unfavorable investment, with a negative IRR over the plant’s lifespan.